Circuit designs implemented within integrated circuit devices (ICs) are routinely tested for functionality. It is common practice to simulate circuit designs for ICs using any of a variety of different Electronic Design Automation (EDA) tools. Typically, such circuit designs are to be used within a larger system. For example, the IC usually is mounted upon a circuit board with one or more other ICs and various other electronic components. It then becomes necessary to ensure that each IC interacts with each other IC, on the circuit board level, appropriately.
To do so, the input/output (I/O) behavior of each IC must be characterized. Simulation data as to the specific circuit design of each individual IC will not convey the information that is needed for board level simulation. Other techniques are necessary to simulate the behavior of ICs at the board level to account for I/O behavior of each individual IC.
One way of expressing I/O behavior of individual pins of an IC is through the use of a standard known as the Input/Output Buffer Information Specification (IBIS). Models that specify the behavior of I/O pins for the IC can be created that conform to IBIS or another available specification. I/O pin models that are created for the I/O pins of an IC can be used to implement transmission line-like simulation of the various signals exchanged between I/O pins of the ICs on a circuit board. The I/O pin models do not reveal the inner workings or functionality of the IC itself.